/** Copyright (C) 2008 Happy Fish / YuQing
 * FastDFS Java Client may be copied only under the terms of the GNU Lesser
 * General Public License (LGPL).
 * Please visit the FastDFS Home Page http://www.csource.org/ for more detail. **/

package org.csource.fastdfs;

import java.io.InputStream;
import java.io.IOException;
import java.io.UnsupportedEncodingException;
import java.security.NoSuchAlgorithmException;
import java.util.Arrays;

import org.csource.common.MyException;
import org.csource.common.NameValuePair;

import java.net.Socket;

/**
* protocol common functions
* @author Happy Fish / YuQing
* @version Version 1.18
*/
public class ProtoCommon {
    /**
    * receive package info
    */
    public static class RecvPackageInfo {
        public byte errno;
        public byte[] body;

        public RecvPackageInfo(byte errno, byte[] body) {
            this.errno = errno;
            this.body = body;
        }
    }

    /**
    * receive header info
    */
    public static class RecvHeaderInfo {
        public byte errno;
        public long body_len;

        public RecvHeaderInfo(byte errno, long body_len) {
            this.errno = errno;
            this.body_len = body_len;
        }
    }

    public static final byte FDFS_PROTO_CMD_QUIT = 82;
    public static final byte TRACKER_PROTO_CMD_SERVER_LIST_GROUP = 91;
    public static final byte TRACKER_PROTO_CMD_SERVER_LIST_STORAGE = 92;
    public static final byte TRACKER_PROTO_CMD_SERVER_DELETE_STORAGE = 93;

    public static final byte TRACKER_PROTO_CMD_SERVICE_QUERY_STORE_WITHOUT_GROUP_ONE = 101;
    public static final byte TRACKER_PROTO_CMD_SERVICE_QUERY_FETCH_ONE = 102;
    public static final byte TRACKER_PROTO_CMD_SERVICE_QUERY_UPDATE = 103;
    public static final byte TRACKER_PROTO_CMD_SERVICE_QUERY_STORE_WITH_GROUP_ONE = 104;
    public static final byte TRACKER_PROTO_CMD_SERVICE_QUERY_FETCH_ALL = 105;
    public static final byte TRACKER_PROTO_CMD_SERVICE_QUERY_STORE_WITHOUT_GROUP_ALL = 106;
    public static final byte TRACKER_PROTO_CMD_SERVICE_QUERY_STORE_WITH_GROUP_ALL = 107;
    public static final byte TRACKER_PROTO_CMD_RESP = 100;
    public static final byte FDFS_PROTO_CMD_ACTIVE_TEST = 111;
    public static final byte STORAGE_PROTO_CMD_UPLOAD_FILE = 11;
    public static final byte STORAGE_PROTO_CMD_DELETE_FILE = 12;
    public static final byte STORAGE_PROTO_CMD_SET_METADATA = 13;
    public static final byte STORAGE_PROTO_CMD_DOWNLOAD_FILE = 14;
    public static final byte STORAGE_PROTO_CMD_GET_METADATA = 15;
    public static final byte STORAGE_PROTO_CMD_UPLOAD_SLAVE_FILE = 21;
    public static final byte STORAGE_PROTO_CMD_QUERY_FILE_INFO = 22;
    public static final byte STORAGE_PROTO_CMD_UPLOAD_APPENDER_FILE = 23; // create appender file
    public static final byte STORAGE_PROTO_CMD_APPEND_FILE = 24; // append file
    public static final byte STORAGE_PROTO_CMD_MODIFY_FILE = 34; // modify appender file
    public static final byte STORAGE_PROTO_CMD_TRUNCATE_FILE = 36; // truncate appender file

    public static final byte STORAGE_PROTO_CMD_RESP = TRACKER_PROTO_CMD_RESP;

    public static final byte FDFS_STORAGE_STATUS_INIT = 0;
    public static final byte FDFS_STORAGE_STATUS_WAIT_SYNC = 1;
    public static final byte FDFS_STORAGE_STATUS_SYNCING = 2;
    public static final byte FDFS_STORAGE_STATUS_IP_CHANGED = 3;
    public static final byte FDFS_STORAGE_STATUS_DELETED = 4;
    public static final byte FDFS_STORAGE_STATUS_OFFLINE = 5;
    public static final byte FDFS_STORAGE_STATUS_ONLINE = 6;
    public static final byte FDFS_STORAGE_STATUS_ACTIVE = 7;
    public static final byte FDFS_STORAGE_STATUS_NONE = 99;

    /**
    * for overwrite all old metadata
    */
    public static final byte STORAGE_SET_METADATA_FLAG_OVERWRITE = 'O';

    /**
    * for replace, insert when the meta item not exist, otherwise update it
    */
    public static final byte STORAGE_SET_METADATA_FLAG_MERGE = 'M';

    public static final int FDFS_PROTO_PKG_LEN_SIZE = 8;
    public static final int FDFS_PROTO_CMD_SIZE = 1;
    public static final int FDFS_GROUP_NAME_MAX_LEN = 16;
    public static final int FDFS_IPADDR_SIZE = 16;
    public static final int FDFS_DOMAIN_NAME_MAX_SIZE = 128;
    public static final int FDFS_VERSION_SIZE = 6;
    public static final int FDFS_STORAGE_ID_MAX_SIZE = 16;

    public static final String FDFS_RECORD_SEPERATOR = "\u0001";
    public static final String FDFS_FIELD_SEPERATOR = "\u0002";

    public static final int TRACKER_QUERY_STORAGE_FETCH_BODY_LEN = FDFS_GROUP_NAME_MAX_LEN + FDFS_IPADDR_SIZE - 1
        + FDFS_PROTO_PKG_LEN_SIZE;
    public static final int TRACKER_QUERY_STORAGE_STORE_BODY_LEN = FDFS_GROUP_NAME_MAX_LEN + FDFS_IPADDR_SIZE
        + FDFS_PROTO_PKG_LEN_SIZE;

    protected static final int PROTO_HEADER_CMD_INDEX = FDFS_PROTO_PKG_LEN_SIZE;
    protected static final int PROTO_HEADER_STATUS_INDEX = FDFS_PROTO_PKG_LEN_SIZE + 1;

    public static final byte FDFS_FILE_EXT_NAME_MAX_LEN = 6;
    public static final byte FDFS_FILE_PREFIX_MAX_LEN = 16;
    public static final byte FDFS_FILE_PATH_LEN = 10;
    public static final byte FDFS_FILENAME_BASE64_LENGTH = 27;
    public static final byte FDFS_TRUNK_FILE_INFO_LEN = 16;

    public static final byte ERR_NO_ENOENT = 2;
    public static final byte ERR_NO_EIO = 5;
    public static final byte ERR_NO_EBUSY = 16;
    public static final byte ERR_NO_EINVAL = 22;
    public static final byte ERR_NO_ENOSPC = 28;
    public static final byte ECONNREFUSED = 61;
    public static final byte ERR_NO_EALREADY = 114;

    public static final long INFINITE_FILE_SIZE = 256 * 1024L * 1024 * 1024 * 1024 * 1024L;
    public static final long APPENDER_FILE_SIZE = INFINITE_FILE_SIZE;
    public static final long TRUNK_FILE_MARK_SIZE = 512 * 1024L * 1024 * 1024 * 1024 * 1024L;
    public static final long NORMAL_LOGIC_FILENAME_LENGTH = FDFS_FILE_PATH_LEN + FDFS_FILENAME_BASE64_LENGTH
        + FDFS_FILE_EXT_NAME_MAX_LEN + 1;
    public static final long TRUNK_LOGIC_FILENAME_LENGTH = NORMAL_LOGIC_FILENAME_LENGTH + FDFS_TRUNK_FILE_INFO_LEN;

    private ProtoCommon() {
    }

    public static String getStorageStatusCaption(byte status) {
        switch (status) {
        case FDFS_STORAGE_STATUS_INIT:
            return "INIT";
        case FDFS_STORAGE_STATUS_WAIT_SYNC:
            return "WAIT_SYNC";
        case FDFS_STORAGE_STATUS_SYNCING:
            return "SYNCING";
        case FDFS_STORAGE_STATUS_IP_CHANGED:
            return "IP_CHANGED";
        case FDFS_STORAGE_STATUS_DELETED:
            return "DELETED";
        case FDFS_STORAGE_STATUS_OFFLINE:
            return "OFFLINE";
        case FDFS_STORAGE_STATUS_ONLINE:
            return "ONLINE";
        case FDFS_STORAGE_STATUS_ACTIVE:
            return "ACTIVE";
        case FDFS_STORAGE_STATUS_NONE:
            return "NONE";
        default:
            return "UNKOWN";
        }
    }

    /**
    * pack header by FastDFS transfer protocol
    * @param cmd which command to send
    * @param pkg_len package body length
    * @param errno status code, should be (byte)0
    * @return packed byte buffer
     * @throws UnsupportedEncodingException if an error occurred
    */
    public static byte[] packHeader(byte cmd, long pkg_len, byte errno) throws UnsupportedEncodingException {
        byte[] header;
        byte[] hex_len;

        header = new byte[FDFS_PROTO_PKG_LEN_SIZE + 2];
        Arrays.fill(header, (byte)0);

        hex_len = ProtoCommon.long2buff(pkg_len);
        System.arraycopy(hex_len, 0, header, 0, hex_len.length);
        header[PROTO_HEADER_CMD_INDEX] = cmd;
        header[PROTO_HEADER_STATUS_INDEX] = errno;
        return header;
    }

    /**
    * receive pack header
    * @param in input stream
    * @param expect_cmd expect response command
    * @param expect_body_len expect response package body length
    * @return RecvHeaderInfo: errno and pkg body length
     * @throws IOException if an error occurred
    */
    public static RecvHeaderInfo recvHeader(InputStream in, byte expect_cmd, long expect_body_len) throws IOException {
        byte[] header;
        int bytes;
        long pkg_len;

        header = new byte[FDFS_PROTO_PKG_LEN_SIZE + 2];

        if ((bytes = in.read(header)) != header.length) {
            throw new IOException("recv package size " + bytes + " != " + header.length);
        }

        if (header[PROTO_HEADER_CMD_INDEX] != expect_cmd) {
            throw new IOException(
                "recv cmd: " + header[PROTO_HEADER_CMD_INDEX] + " is not correct, expect cmd: " + expect_cmd);
        }

        if (header[PROTO_HEADER_STATUS_INDEX] != 0) {
            return new RecvHeaderInfo(header[PROTO_HEADER_STATUS_INDEX], 0);
        }

        pkg_len = ProtoCommon.buff2long(header, 0);
        if (pkg_len < 0) {
            throw new IOException("recv body length: " + pkg_len + " < 0!");
        }

        if (expect_body_len >= 0 && pkg_len != expect_body_len) {
            throw new IOException(
                "recv body length: " + pkg_len + " is not correct, expect length: " + expect_body_len);
        }

        return new RecvHeaderInfo((byte)0, pkg_len);
    }

    /**
    * receive whole pack
    * @param in input stream
    * @param expect_cmd expect response command
    * @param expect_body_len expect response package body length
    * @return RecvPackageInfo: errno and reponse body(byte buff)
     * @throws IOException if an error occurred
    */
    public static RecvPackageInfo recvPackage(InputStream in, byte expect_cmd, long expect_body_len)
        throws IOException {
        RecvHeaderInfo header = recvHeader(in, expect_cmd, expect_body_len);
        if (header.errno != 0) {
            return new RecvPackageInfo(header.errno, null);
        }

        byte[] body = new byte[(int)header.body_len];
        int totalBytes = 0;
        int remainBytes = (int)header.body_len;
        int bytes;

        while (totalBytes < header.body_len) {
            if ((bytes = in.read(body, totalBytes, remainBytes)) < 0) {
                break;
            }

            totalBytes += bytes;
            remainBytes -= bytes;
        }

        if (totalBytes != header.body_len) {
            throw new IOException("recv package size " + totalBytes + " != " + header.body_len);
        }

        return new RecvPackageInfo((byte)0, body);
    }

    /**
    * split metadata to name value pair array
    * @param meta_buff metadata
    * @return name value pair array
    */
    public static NameValuePair[] split_metadata(String meta_buff) {
        return split_metadata(meta_buff, FDFS_RECORD_SEPERATOR, FDFS_FIELD_SEPERATOR);
    }

    /**
    * split metadata to name value pair array
    * @param meta_buff metadata
    * @param recordSeperator record/row seperator
    * @param filedSeperator field/column seperator
    * @return name value pair array
    */
    public static NameValuePair[] split_metadata(String meta_buff, String recordSeperator, String filedSeperator) {
        String[] rows;
        String[] cols;
        NameValuePair[] meta_list;

        rows = meta_buff.split(recordSeperator);
        meta_list = new NameValuePair[rows.length];
        for (int i = 0; i < rows.length; i++) {
            cols = rows[i].split(filedSeperator, 2);
            meta_list[i] = new NameValuePair(cols[0]);
            if (cols.length == 2) {
                meta_list[i].setValue(cols[1]);
            }
        }

        return meta_list;
    }

    /**
    * pack metadata array to string
    * @param meta_list metadata array
    * @return packed metadata
    */
    public static String pack_metadata(NameValuePair[] meta_list) {
        if (meta_list.length == 0) {
            return "";
        }

        StringBuffer sb = new StringBuffer(32 * meta_list.length);
        sb.append(meta_list[0].getName()).append(FDFS_FIELD_SEPERATOR).append(meta_list[0].getValue());
        for (int i = 1; i < meta_list.length; i++) {
            sb.append(FDFS_RECORD_SEPERATOR);
            sb.append(meta_list[i].getName()).append(FDFS_FIELD_SEPERATOR).append(meta_list[i].getValue());
        }

        return sb.toString();
    }

    /**
    * send quit command to server and close socket
    * @param sock the Socket object
     * @throws IOException if an error occurred
    */
    public static void closeSocket(Socket sock) throws IOException {
        byte[] header;
        header = packHeader(FDFS_PROTO_CMD_QUIT, 0, (byte)0);
        sock.getOutputStream().write(header);
        sock.close();
    }

    /**
    * send ACTIVE_TEST command to server, test if network is ok and the server is alive
    * @param sock the Socket object
    * @return boolean
     * @throws IOException if an error occurred
    */
    public static boolean activeTest(Socket sock) throws IOException {
        byte[] header;
        header = packHeader(FDFS_PROTO_CMD_ACTIVE_TEST, 0, (byte)0);
        sock.getOutputStream().write(header);

        RecvHeaderInfo headerInfo = recvHeader(sock.getInputStream(), TRACKER_PROTO_CMD_RESP, 0);
        return headerInfo.errno == 0 ? true : false;
    }

    /**
    * long convert to buff (big-endian)
    * @param n long number
    * @return 8 bytes buff
    */
    public static byte[] long2buff(long n) {
        byte[] bs;

        bs = new byte[8];
        bs[0] = (byte)((n >> 56) & 0xFF);
        bs[1] = (byte)((n >> 48) & 0xFF);
        bs[2] = (byte)((n >> 40) & 0xFF);
        bs[3] = (byte)((n >> 32) & 0xFF);
        bs[4] = (byte)((n >> 24) & 0xFF);
        bs[5] = (byte)((n >> 16) & 0xFF);
        bs[6] = (byte)((n >> 8) & 0xFF);
        bs[7] = (byte)(n & 0xFF);

        return bs;
    }

    /**
    * buff convert to long
    * @param bs the buffer (big-endian)
    * @param offset the start position based 0
    * @return long number
    */
    public static long buff2long(byte[] bs, int offset) {
        return (((long)(bs[offset] >= 0 ? bs[offset] : 256 + bs[offset])) << 56)
            | (((long)(bs[offset + 1] >= 0 ? bs[offset + 1] : 256 + bs[offset + 1])) << 48)
            | (((long)(bs[offset + 2] >= 0 ? bs[offset + 2] : 256 + bs[offset + 2])) << 40)
            | (((long)(bs[offset + 3] >= 0 ? bs[offset + 3] : 256 + bs[offset + 3])) << 32)
            | (((long)(bs[offset + 4] >= 0 ? bs[offset + 4] : 256 + bs[offset + 4])) << 24)
            | (((long)(bs[offset + 5] >= 0 ? bs[offset + 5] : 256 + bs[offset + 5])) << 16)
            | (((long)(bs[offset + 6] >= 0 ? bs[offset + 6] : 256 + bs[offset + 6])) << 8)
            | ((long)(bs[offset + 7] >= 0 ? bs[offset + 7] : 256 + bs[offset + 7]));
    }

    /**
    * buff convert to int
    * @param bs the buffer (big-endian)
    * @param offset the start position based 0
    * @return int number
    */
    public static int buff2int(byte[] bs, int offset) {
        return (((int)(bs[offset] >= 0 ? bs[offset] : 256 + bs[offset])) << 24)
            | (((int)(bs[offset + 1] >= 0 ? bs[offset + 1] : 256 + bs[offset + 1])) << 16)
            | (((int)(bs[offset + 2] >= 0 ? bs[offset + 2] : 256 + bs[offset + 2])) << 8)
            | ((int)(bs[offset + 3] >= 0 ? bs[offset + 3] : 256 + bs[offset + 3]));
    }

    /**
    * buff convert to ip address
    * @param bs the buffer (big-endian)
    * @param offset the start position based 0
    * @return ip address
    */
    public static String getIpAddress(byte[] bs, int offset) {
        if (bs[0] == 0 || bs[3] == 0) // storage server ID
        {
            return "";
        }

        int n;
        StringBuilder sbResult = new StringBuilder(16);
        for (int i = offset; i < offset + 4; i++) {
            n = (bs[i] >= 0) ? bs[i] : 256 + bs[i];
            if (sbResult.length() > 0) {
                sbResult.append(".");
            }
            sbResult.append(String.valueOf(n));
        }

        return sbResult.toString();
    }

    /**
    * md5 function
    * @param source the input buffer
    * @return md5 string
    */
    public static String md5(byte[] source) throws NoSuchAlgorithmException {
        char hexDigits[] = {'0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'a', 'b', 'c', 'd', 'e', 'f'};
        java.security.MessageDigest md = java.security.MessageDigest.getInstance("MD5");
        md.update(source);
        byte tmp[] = md.digest();
        char str[] = new char[32];
        int k = 0;
        for (int i = 0; i < 16; i++) {
            str[k++] = hexDigits[tmp[i] >>> 4 & 0xf];
            str[k++] = hexDigits[tmp[i] & 0xf];
        }

        return new String(str);
    }

    /**
    * get token for file URL
    * @param remote_filename the filename return by FastDFS server
    * @param ts unix timestamp, unit: second
    * @param secret_key the secret key
    * @return token string
     * @throws UnsupportedEncodingException if an error occurred
     * @throws NoSuchAlgorithmException if an error occurred
     * @throws MyException if an error occurred
     */
    public static String getToken(String remote_filename, int ts, String secret_key)
        throws UnsupportedEncodingException, NoSuchAlgorithmException, MyException {
        byte[] bsFilename = remote_filename.getBytes(ClientGlobal.g_charset);
        byte[] bsKey = secret_key.getBytes(ClientGlobal.g_charset);
        byte[] bsTimestamp = (new Integer(ts)).toString().getBytes(ClientGlobal.g_charset);

        byte[] buff = new byte[bsFilename.length + bsKey.length + bsTimestamp.length];
        System.arraycopy(bsFilename, 0, buff, 0, bsFilename.length);
        System.arraycopy(bsKey, 0, buff, bsFilename.length, bsKey.length);
        System.arraycopy(bsTimestamp, 0, buff, bsFilename.length + bsKey.length, bsTimestamp.length);

        return md5(buff);
    }

    /**
    * generate slave filename
    * @param master_filename the master filename to generate the slave filename
    * @param prefix_name the prefix name to generate the slave filename
    * @param ext_name the extension name of slave filename, null for same as the master extension name
    * @return slave filename string
     * @throws MyException if an error occurred
    */
    public static String genSlaveFilename(String master_filename, String prefix_name, String ext_name)
        throws MyException {
        String true_ext_name;
        int dotIndex;

        if (master_filename.length() < 28 + FDFS_FILE_EXT_NAME_MAX_LEN) {
            throw new MyException("master filename \"" + master_filename + "\" is invalid");
        }

        dotIndex = master_filename.indexOf('.', master_filename.length() - (FDFS_FILE_EXT_NAME_MAX_LEN + 1));
        if (ext_name != null) {
            if (ext_name.length() == 0) {
                true_ext_name = "";
            } else if (ext_name.charAt(0) == '.') {
                true_ext_name = ext_name;
            } else {
                true_ext_name = "." + ext_name;
            }
        } else {
            if (dotIndex < 0) {
                true_ext_name = "";
            } else {
                true_ext_name = master_filename.substring(dotIndex);
            }
        }

        if (true_ext_name.length() == 0 && prefix_name.equals("-m")) {
            throw new MyException("prefix_name \"" + prefix_name + "\" is invalid");
        }

        if (dotIndex < 0) {
            return master_filename + prefix_name + true_ext_name;
        } else {
            return master_filename.substring(0, dotIndex) + prefix_name + true_ext_name;
        }
    }
}
